Cardiac measurement by radiographic by radiographic method is the most acurate procedure by which physicianscan obtaine data regarding cardiac size in life. In order to determine the standard values among Koreans, cardiacmensuration by the radiographic frontal cardiac area method was carried out on 225 healthy Korean infants, 111 ofwhom were males and 114 were females. The results were as follows; 1. Transverse diameter at one month of age is 4.56±0.12cm inn male and 5.00±0.19cm in female and at eleven months of age 7.35±0.12cm in male, 7.42±0.09cm infemale. 2. Broad diameter at one month of age is 3.94±0.15cm in male and 4.53±0.19cm in female and at elevenmonths of age 5.82±0.14cm in male, 5.94±0.14cm in female. 3. Long diameter at one month of age is 3.94±0.15cmin male and 5.30±0.23cm in female and at eleven months of age 7.67±0.15cm in male, 7.55±0.11 cm in female. 4.The obliquity of the cardiac axis shows no significant difference in age and sex. The range of the measurementsare between 31degrees and 37degrees. 5. Frontal cardiac area at one month of age is 14.36±1.11cm2 in male and18.97±0.14cm2 in female and at eleven months of age 35.27±1.21cm2 in male, 35.43±0.45cm2 in female. 6. In everydiameter and frontal cardiac area, except the obliquity of the cardiac axis, show greater value in female at theage of 1 month, but show almost same value in male as in female at the age of 11 months.